It is common practice in boating to remove boats from the water at the conclusion of the boating activity, either for transport of the boat to a different location, or for dry storage on the beach, a boat hoist or boat trailer. In these boats with drain openings in the transom, it is also common practice when the boat is taken out to remove the drain plug from the drain opening. This permits any water which has collected in the interior of the boat to drain away. It is also common to leave the drain opening unplugged while the boat is out of the water, so as to permit drainge of any additional water, such as rain water, that might otherwise collect if the drain were plugged.
It not infrequently happens that when the boat is next launched, the insertion of the plug into the drain opening has been overlooked. As a consequence, as the boat enters the water, water flows inwardly through the drain opening and begins to fill the boat. If not checked, it is possible for the boat to sink. At the least, damage to components and possessions by flooding can occur, to say nothing as to the embarrassment of the owner or operator.